Ghost Rockets: Explosive Halloween STEM for Kids

Blast off into Halloween with a science experiment that will surely amaze the kids! Flying ghost rockets are easy to set up but jam-packed with explosive STEM fun.

Ghost Rocket Blast Off

After the paint bombs art and DIY lava lamp activities, my kids have been itching to use Alka Seltzer tablets again. They know that exciting things happen when you combine water with Alka Seltzer tablets.

Let’s dive in to see how you can surprise and impress your kids this Halloween with ghost rockets!

How to Make Ghost Rockets



1. Draw ghost faces on the film canisters with the black permanent marker. Don’t try using washable or dry erase markers, they will come off when the film canisters get wet.

Ghost Rocket Blast Faces

2. Fill the film canisters about ¼-⅓ of the way with water. You don’t need to be exact!

3. Break an Alka Seltzer tablet into 2-4 pieces. 

4. Drop the Alka Seltzer tablet in the film canister and close the lid quickly.

Ghost Rocket Alka Seltzer Tablet

5. Flip the film canister over, lid down, and stand back.

Ghost Rocket CO2 Buildup

6. Watch the ghost rocket blast off into the air!

Ghost Rocket Midair (1)

How high did your ghost rockets fly? There is a lot of force propelling the film canisters upward. Just look at the splatter!

Ghost Rocket Water Blast

I made the mistake of putting my hands over the ghost rocket in an attempt to move it before it exploded. The film canister ended up shooting into my hand and I could feel its impact even after an hour. So make sure you back up to avoid getting hit with the rocket!

The kids had so much fun making the ghost rockets take off into the air. Since we were blasting off next to the swimming pool, we eventually tried to shoot the ghosts into the water. It was such fun watching the ghost rockets land in the pool and then my kids would take turns fishing them out with the net.

Ghost Rocket Midair (2)

Science Behind the Ghost Rockets

Just like we saw in the paint bombs activity, when Alka Seltzer mixes with water, CO2 is released. When the film canister cannot hold any more gas, the lid pops off and gas rushes out. This creates the explosion and the force of the gas rushing out causes the ghost rocket to blast off into the air.


If you are on the fence about buying film canisters for these experiments, I assure you that it’s money well spent. Besides using them for science activities, we also use the film canisters to store glitter, sequins, and beads as well as use them to hold paint for art projects.

The ghost rockets make a fun, non-spooky Halloween STEM that the kids will want to do over and over again. Just make sure your kids wash their hands afterward!


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